The present embodiment relates to roller levelers. It finds particular application in conjunction with cassette roller levelers which have and use two different roll cartridges or cassettes which have rolls of different diameters and roll center distances. An example of a roller leveler which may be used with the present disclosure is shown in U.S. Pat. No. 7,637,133 which is hereby incorporated by reference and will be described with particular reference thereto. However, it is to be appreciated that the present embodiment is also amenable to other like applications.
Metal is formed into strips by a process known as rolling, wherein the strip is passed between a pair of work rolls of a rolling mill to reduce its cross-sectional thickness. In the process, the strip is elongated and rolling continues until the strip is reduced to the cross-sectional thickness desired. This rolling process may start with heated billets or slabs of metal, wherein the metal is rolled at a very high temperature, or it may start with previously rolled strip wherein the strip is passed between work rolls in the cold state. In either event, when the strip exits from the mill, it may be convolutedly wrapped to form a coil. It is well established that the flatter the strip is prior to a subsequent manufacturing operation, the more accurate and satisfactory will be the end product of that operation. Thus, even where portions of steel strip are deep drawn, they do not draw as satisfactorily if the strip initially is not substantially flat before the draw.
A cassette roller leveler used to flatten and level metal strips typically includes multiple pairs of offset work rollers or rolls which are positioned within one or more cassettes or cartridges which can be changed out in the roller leveler. Different size levelers can have different quantities of work rolls and back-up rolls. For example, the upper rolls can be offset one-half the distance between a pair of adjacent lower rolls. A metal strip passes between the upper and lower rolls to be leveled. The number and spacing of the rolls depend on the thickness and strength of the metal strip. Typically, as the strip thickness decreases, the spacing of the rolls, as well as the roll diameter, decrease. As the strip passes between the rolls, it is bent up and down multiple times before it exits the leveler. This reverse bending beyond the yield point of the material is the mechanism whereby the strip is flattened.
Existing cassette levelers use one main frame to house two different roll cartridges, which have rolls with different diameters and center distances. To make for a more economical design, these machines use one set of motors/reducers to drive whichever cartridge currently resides in the machine. During changing out of the cartridges, the portions of the drive shafts that remain with the reducers need to be supported by a positioning spindle support that is designed to support the drive shafts as well as individually change the position of each drive shaft to accommodate the desired cartridge and the position and diameter of the rolls of the cartridge. Most existing cassette levelers pull the drive shaft out with the work roll cassettes. This method requires extra space (because of drive shaft length) and is more expensive because two (2) sets of drive shafts are required.
Thus, there is a need for a roller leveler with common different roll cartridges which has a drive shaft positioning support which shifts the location of drive shafts during cartridge exchanges to match the roll centers of the cartridge being inserted and which overcomes the above-mentioned deficiencies while providing better and more advantageous overall results.